Nimesulide adsorbed on silica aerogel using supercritical carbon dioxide

► We loaded silica aerogel with nimesulide, a poorly water-soluble drug, using supercritical CO2 adsorption to form new kinds of drug delivery systems. ► We measured adsorption isotherms and adsorption kinetics and we described the curves by models. ► The sorption process was well described by a pseudo-second-order model. ► The drug/silica aerogel composites were characterized by different analytical techniques. ► The release rate of nimesulide from the composite, evaluated by in vitro dissolution tests, is much faster than that of the crystalline drug.